FIG. 9 shows in a view obliquely from above a printed circuit board 101, which is populated on its front side 102 and is not populated on its rear side 103. The front side is populated in a central region with a plurality of light emitting diodes 104 and, around the light emitting diodes 104, with a plurality of, also different, electronic components 105. The electronic components 105 may have been applied to the front side 102 by means of reflow soldering, for example. Moreover, a plug connection element 106 is secured to an edge region of the front side 102, and in a manner oriented toward the outside. By means of the plug connection element 106, the electrically operable elements on the front side 102 (light emitting diodes 104 and electronic components 105) can be supplied with a current or a voltage. For this purpose, the front side is provided with a conductor track or conduction structure (not shown) which electrically connects the electrically operable elements 104, 105 to one another and to the plug connection element 106.
The printed circuit board 101, for the securing thereof, is placed and screwed by its rear side 103 onto a support, e.g. a heat sink. Before that, a ring cover 108 is placed thereon as is explained in greater detail with reference to FIG. 2. For the screw connection, the printed circuit board 101 here has two screw bushings 107.
FIG. 10 shows in a view obliquely from above the printed circuit board 101 with a ring-shaped ring cover 108 covering the electronic components 105. The printed circuit board 101 and the ring cover 108 can also be designated as an LED module. An inner wall 109 of the ring cover 108 serves as a reflector wall for the light emitting diodes 104. The ring cover 108 likewise has two screw holes 110, such that two screws 111 can respectively be led through the screw holes 110, 107 and be screwed to the support. The tightened screws press the ring cover 108 in a sealing fashion onto the front side 102 of the printed circuit board 101 and the printed circuit board 101 by its rear side 103 onto the support.
For electrical contact-making, the ring cover additionally has a lateral insertion opening 112, through which the plug connection element 106 is accessible and through which e.g. a matching mating plug connection element can be inserted.
The printed circuit board 101 shown has the disadvantage that, for the lateral electrical contact-making, it is necessary to provide a corresponding volume alongside the printed circuit board 101 or the ring cover 108 for accommodating the external mating plug connection element and for cable routing. Moreover, the plug connection element 106 considerably increases a structural height. On the printed circuit board 101, area occupancy is also impaired by the provision of the screw holes 107. Furthermore, the screws 111 bring about a disadvantageous appearance in plan view.
Incandescent-lamp retrofit lamps are known which have a heat sink into which a driver cavity is integrated. A printed circuit board populated with at least one light emitting diode is mounted on a front-side support area of the heat sink. The driver cavity is closed off toward the rear by a base, via which a driver situated in the driver cavity can be connected to a power supply voltage. The outputs of the driver are electrically connected to the at least one light emitting diode in order to supply the light emitting diode with a suitable current or voltage signal. For this purpose, the heat sink contains a cutout in the form of a bushing between the driver cavity and the support area, through which appropriate cables can be led. In order to secure the printed circuit board to the heat sink, the printed circuit board is laterally clamped into the heat sink, screwed to the heat sink or adhesively bonded to the heat sink.
What is disadvantageous in the case of such an incandescent-lamp retrofit lamp is that the wiring can be implemented only in a comparatively complex fashion, e.g. owing to insertion and soldering of the cables. Moreover, securing the printed circuit board to the heat sink is comparatively complex, e.g. as a result of a necessary provision of screws and tool in the case of a screw connection and as a result of a comparatively small size of the screws (e.g. M3 or M4).